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-rw-r--r--arch/x86/kernel/reboot_32.c413
1 files changed, 413 insertions, 0 deletions
diff --git a/arch/x86/kernel/reboot_32.c b/arch/x86/kernel/reboot_32.c
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1/*
2 * linux/arch/i386/kernel/reboot.c
3 */
4
5#include <linux/mm.h>
6#include <linux/module.h>
7#include <linux/delay.h>
8#include <linux/init.h>
9#include <linux/interrupt.h>
10#include <linux/mc146818rtc.h>
11#include <linux/efi.h>
12#include <linux/dmi.h>
13#include <linux/ctype.h>
14#include <linux/pm.h>
15#include <linux/reboot.h>
16#include <asm/uaccess.h>
17#include <asm/apic.h>
18#include <asm/desc.h>
19#include "mach_reboot.h"
20#include <asm/reboot_fixups.h>
21#include <asm/reboot.h>
22
23/*
24 * Power off function, if any
25 */
26void (*pm_power_off)(void);
27EXPORT_SYMBOL(pm_power_off);
28
29static int reboot_mode;
30static int reboot_thru_bios;
31
32#ifdef CONFIG_SMP
33static int reboot_cpu = -1;
34#endif
35static int __init reboot_setup(char *str)
36{
37 while(1) {
38 switch (*str) {
39 case 'w': /* "warm" reboot (no memory testing etc) */
40 reboot_mode = 0x1234;
41 break;
42 case 'c': /* "cold" reboot (with memory testing etc) */
43 reboot_mode = 0x0;
44 break;
45 case 'b': /* "bios" reboot by jumping through the BIOS */
46 reboot_thru_bios = 1;
47 break;
48 case 'h': /* "hard" reboot by toggling RESET and/or crashing the CPU */
49 reboot_thru_bios = 0;
50 break;
51#ifdef CONFIG_SMP
52 case 's': /* "smp" reboot by executing reset on BSP or other CPU*/
53 if (isdigit(*(str+1))) {
54 reboot_cpu = (int) (*(str+1) - '0');
55 if (isdigit(*(str+2)))
56 reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
57 }
58 /* we will leave sorting out the final value
59 when we are ready to reboot, since we might not
60 have set up boot_cpu_id or smp_num_cpu */
61 break;
62#endif
63 }
64 if((str = strchr(str,',')) != NULL)
65 str++;
66 else
67 break;
68 }
69 return 1;
70}
71
72__setup("reboot=", reboot_setup);
73
74/*
75 * Reboot options and system auto-detection code provided by
76 * Dell Inc. so their systems "just work". :-)
77 */
78
79/*
80 * Some machines require the "reboot=b" commandline option, this quirk makes that automatic.
81 */
82static int __init set_bios_reboot(struct dmi_system_id *d)
83{
84 if (!reboot_thru_bios) {
85 reboot_thru_bios = 1;
86 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
87 }
88 return 0;
89}
90
91static struct dmi_system_id __initdata reboot_dmi_table[] = {
92 { /* Handle problems with rebooting on Dell E520's */
93 .callback = set_bios_reboot,
94 .ident = "Dell E520",
95 .matches = {
96 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
97 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
98 },
99 },
100 { /* Handle problems with rebooting on Dell 1300's */
101 .callback = set_bios_reboot,
102 .ident = "Dell PowerEdge 1300",
103 .matches = {
104 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
105 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
106 },
107 },
108 { /* Handle problems with rebooting on Dell 300's */
109 .callback = set_bios_reboot,
110 .ident = "Dell PowerEdge 300",
111 .matches = {
112 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
113 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
114 },
115 },
116 { /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
117 .callback = set_bios_reboot,
118 .ident = "Dell OptiPlex 745",
119 .matches = {
120 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
121 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
122 DMI_MATCH(DMI_BOARD_NAME, "0WF810"),
123 },
124 },
125 { /* Handle problems with rebooting on Dell 2400's */
126 .callback = set_bios_reboot,
127 .ident = "Dell PowerEdge 2400",
128 .matches = {
129 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
130 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
131 },
132 },
133 { /* Handle problems with rebooting on HP laptops */
134 .callback = set_bios_reboot,
135 .ident = "HP Compaq Laptop",
136 .matches = {
137 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
138 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
139 },
140 },
141 { }
142};
143
144static int __init reboot_init(void)
145{
146 dmi_check_system(reboot_dmi_table);
147 return 0;
148}
149
150core_initcall(reboot_init);
151
152/* The following code and data reboots the machine by switching to real
153 mode and jumping to the BIOS reset entry point, as if the CPU has
154 really been reset. The previous version asked the keyboard
155 controller to pulse the CPU reset line, which is more thorough, but
156 doesn't work with at least one type of 486 motherboard. It is easy
157 to stop this code working; hence the copious comments. */
158
159static unsigned long long
160real_mode_gdt_entries [3] =
161{
162 0x0000000000000000ULL, /* Null descriptor */
163 0x00009a000000ffffULL, /* 16-bit real-mode 64k code at 0x00000000 */
164 0x000092000100ffffULL /* 16-bit real-mode 64k data at 0x00000100 */
165};
166
167static struct Xgt_desc_struct
168real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
169real_mode_idt = { 0x3ff, 0 },
170no_idt = { 0, 0 };
171
172
173/* This is 16-bit protected mode code to disable paging and the cache,
174 switch to real mode and jump to the BIOS reset code.
175
176 The instruction that switches to real mode by writing to CR0 must be
177 followed immediately by a far jump instruction, which set CS to a
178 valid value for real mode, and flushes the prefetch queue to avoid
179 running instructions that have already been decoded in protected
180 mode.
181
182 Clears all the flags except ET, especially PG (paging), PE
183 (protected-mode enable) and TS (task switch for coprocessor state
184 save). Flushes the TLB after paging has been disabled. Sets CD and
185 NW, to disable the cache on a 486, and invalidates the cache. This
186 is more like the state of a 486 after reset. I don't know if
187 something else should be done for other chips.
188
189 More could be done here to set up the registers as if a CPU reset had
190 occurred; hopefully real BIOSs don't assume much. */
191
192static unsigned char real_mode_switch [] =
193{
194 0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */
195 0x66, 0x83, 0xe0, 0x11, /* andl $0x00000011,%eax */
196 0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000,%eax */
197 0x66, 0x0f, 0x22, 0xc0, /* movl %eax,%cr0 */
198 0x66, 0x0f, 0x22, 0xd8, /* movl %eax,%cr3 */
199 0x66, 0x0f, 0x20, 0xc3, /* movl %cr0,%ebx */
200 0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60, /* andl $0x60000000,%ebx */
201 0x74, 0x02, /* jz f */
202 0x0f, 0x09, /* wbinvd */
203 0x24, 0x10, /* f: andb $0x10,al */
204 0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */
205};
206static unsigned char jump_to_bios [] =
207{
208 0xea, 0x00, 0x00, 0xff, 0xff /* ljmp $0xffff,$0x0000 */
209};
210
211/*
212 * Switch to real mode and then execute the code
213 * specified by the code and length parameters.
214 * We assume that length will aways be less that 100!
215 */
216void machine_real_restart(unsigned char *code, int length)
217{
218 local_irq_disable();
219
220 /* Write zero to CMOS register number 0x0f, which the BIOS POST
221 routine will recognize as telling it to do a proper reboot. (Well
222 that's what this book in front of me says -- it may only apply to
223 the Phoenix BIOS though, it's not clear). At the same time,
224 disable NMIs by setting the top bit in the CMOS address register,
225 as we're about to do peculiar things to the CPU. I'm not sure if
226 `outb_p' is needed instead of just `outb'. Use it to be on the
227 safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
228 */
229
230 spin_lock(&rtc_lock);
231 CMOS_WRITE(0x00, 0x8f);
232 spin_unlock(&rtc_lock);
233
234 /* Remap the kernel at virtual address zero, as well as offset zero
235 from the kernel segment. This assumes the kernel segment starts at
236 virtual address PAGE_OFFSET. */
237
238 memcpy (swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,
239 sizeof (swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
240
241 /*
242 * Use `swapper_pg_dir' as our page directory.
243 */
244 load_cr3(swapper_pg_dir);
245
246 /* Write 0x1234 to absolute memory location 0x472. The BIOS reads
247 this on booting to tell it to "Bypass memory test (also warm
248 boot)". This seems like a fairly standard thing that gets set by
249 REBOOT.COM programs, and the previous reset routine did this
250 too. */
251
252 *((unsigned short *)0x472) = reboot_mode;
253
254 /* For the switch to real mode, copy some code to low memory. It has
255 to be in the first 64k because it is running in 16-bit mode, and it
256 has to have the same physical and virtual address, because it turns
257 off paging. Copy it near the end of the first page, out of the way
258 of BIOS variables. */
259
260 memcpy ((void *) (0x1000 - sizeof (real_mode_switch) - 100),
261 real_mode_switch, sizeof (real_mode_switch));
262 memcpy ((void *) (0x1000 - 100), code, length);
263
264 /* Set up the IDT for real mode. */
265
266 load_idt(&real_mode_idt);
267
268 /* Set up a GDT from which we can load segment descriptors for real
269 mode. The GDT is not used in real mode; it is just needed here to
270 prepare the descriptors. */
271
272 load_gdt(&real_mode_gdt);
273
274 /* Load the data segment registers, and thus the descriptors ready for
275 real mode. The base address of each segment is 0x100, 16 times the
276 selector value being loaded here. This is so that the segment
277 registers don't have to be reloaded after switching to real mode:
278 the values are consistent for real mode operation already. */
279
280 __asm__ __volatile__ ("movl $0x0010,%%eax\n"
281 "\tmovl %%eax,%%ds\n"
282 "\tmovl %%eax,%%es\n"
283 "\tmovl %%eax,%%fs\n"
284 "\tmovl %%eax,%%gs\n"
285 "\tmovl %%eax,%%ss" : : : "eax");
286
287 /* Jump to the 16-bit code that we copied earlier. It disables paging
288 and the cache, switches to real mode, and jumps to the BIOS reset
289 entry point. */
290
291 __asm__ __volatile__ ("ljmp $0x0008,%0"
292 :
293 : "i" ((void *) (0x1000 - sizeof (real_mode_switch) - 100)));
294}
295#ifdef CONFIG_APM_MODULE
296EXPORT_SYMBOL(machine_real_restart);
297#endif
298
299static void native_machine_shutdown(void)
300{
301#ifdef CONFIG_SMP
302 int reboot_cpu_id;
303
304 /* The boot cpu is always logical cpu 0 */
305 reboot_cpu_id = 0;
306
307 /* See if there has been given a command line override */
308 if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
309 cpu_isset(reboot_cpu, cpu_online_map)) {
310 reboot_cpu_id = reboot_cpu;
311 }
312
313 /* Make certain the cpu I'm rebooting on is online */
314 if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
315 reboot_cpu_id = smp_processor_id();
316 }
317
318 /* Make certain I only run on the appropriate processor */
319 set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));
320
321 /* O.K. Now that I'm on the appropriate processor, stop
322 * all of the others, and disable their local APICs.
323 */
324
325 smp_send_stop();
326#endif /* CONFIG_SMP */
327
328 lapic_shutdown();
329
330#ifdef CONFIG_X86_IO_APIC
331 disable_IO_APIC();
332#endif
333}
334
335void __attribute__((weak)) mach_reboot_fixups(void)
336{
337}
338
339static void native_machine_emergency_restart(void)
340{
341 if (!reboot_thru_bios) {
342 if (efi_enabled) {
343 efi.reset_system(EFI_RESET_COLD, EFI_SUCCESS, 0, NULL);
344 load_idt(&no_idt);
345 __asm__ __volatile__("int3");
346 }
347 /* rebooting needs to touch the page at absolute addr 0 */
348 *((unsigned short *)__va(0x472)) = reboot_mode;
349 for (;;) {
350 mach_reboot_fixups(); /* for board specific fixups */
351 mach_reboot();
352 /* That didn't work - force a triple fault.. */
353 load_idt(&no_idt);
354 __asm__ __volatile__("int3");
355 }
356 }
357 if (efi_enabled)
358 efi.reset_system(EFI_RESET_WARM, EFI_SUCCESS, 0, NULL);
359
360 machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
361}
362
363static void native_machine_restart(char * __unused)
364{
365 machine_shutdown();
366 machine_emergency_restart();
367}
368
369static void native_machine_halt(void)
370{
371}
372
373static void native_machine_power_off(void)
374{
375 if (pm_power_off) {
376 machine_shutdown();
377 pm_power_off();
378 }
379}
380
381
382struct machine_ops machine_ops = {
383 .power_off = native_machine_power_off,
384 .shutdown = native_machine_shutdown,
385 .emergency_restart = native_machine_emergency_restart,
386 .restart = native_machine_restart,
387 .halt = native_machine_halt,
388};
389
390void machine_power_off(void)
391{
392 machine_ops.power_off();
393}
394
395void machine_shutdown(void)
396{
397 machine_ops.shutdown();
398}
399
400void machine_emergency_restart(void)
401{
402 machine_ops.emergency_restart();
403}
404
405void machine_restart(char *cmd)
406{
407 machine_ops.restart(cmd);
408}
409
410void machine_halt(void)
411{
412 machine_ops.halt();
413}